duck.html.components.utils.caching

Module for caching components.

Module Contents

Functions

CachedComponent	This is a nested function which you can use directly with component classes without the need of using cached_component decorator.
cached_component	Decorator for returning cached components.
make_cache_key	Returns a cache key.

Data

DEFAULT_CACHE_BACKEND

API

duck.html.components.utils.caching.CachedComponent(component_cls: Type, **cache_options)

This is a nested function which you can use directly with component classes without the need of using cached_component decorator.

Example:

cached_btn_func = CachedComponent(
    Button,
    namespace="welcome-btn",
    targets=["id", "text"],
) # Returns function for retrieving or creating the button instance.

btn = cached_btn_func(id="my-btn", text="Hello world")
btn.is_from_cache() # Returns False for the first time and True otherwise
btn.is_a_copy() # Returns True by default.

exception duck.html.components.utils.caching.ComponentCachingError

Bases: Exception

Raised upon component caching error.

Initialization

Initialize self. See help(type(self)) for accurate signature.

duck.html.components.utils.caching.DEFAULT_CACHE_BACKEND

‘InMemoryCache(…)’

duck.html.components.utils.caching.cached_component(targets: Optional[List[Union[str, Callable]]] = None, cache_backend: Optional[Any] = None, expiry: Optional[float] = None, namespace: Optional[Union[str, Callable]] = None, ignore_args: Optional[List[int]] = None, ignore_kwargs: Optional[List[str]] = None, skip_cache_attr: str = 'skip_cache', on_cache_result: Optional[Callable] = None, freeze: bool = False, return_copy: bool = True, _no_caching: bool = False)

Decorator for returning cached components.

Create a new instance or return a cached instance.

Parameters:

• targets –

  These are component keyword arguments to focus on when caching or a custom caching callable which returns cache value. Example

  targets = ["some_keyword_arg", <custom_callable>]
  

• cache_backend – A custom cache backend which implements methods get and set. If None, default cache backend is used.

• expiry – The expiry for cache keys. Defaults to None.

• namespace – Optional string or callable returning a namespace prefix for keys. Use namespace for grouping and easy bulky cache invalidation.

• ignore_args – Indices to ignore in arguments. For example to ignore first argument when caching, [0] may be parsed as ignore_args.

• ignore_kwargs – Keyword arguments keys to ignore when caching.

• skip_cache_attr – Optional component attribute to skip caching (for debugging). This defaults to skip_cache, meaning, if component.skip_cache=True then, cache is skipped for that component.

• on_cache_result – This is a callable that can be executed upon receiving a result from cache. If some data needs to be reinitialized, you can do this here.

duck.html.components.utils.caching.make_cache_key(component_cls, args: Any, kwargs: Dict[str, Any], namespace: Optional[str] = None) → Tuple

Returns a cache key.